Improvement in relay-magnets



Case 723.

T. A. EDISON.

Relay Magnets.

N0. 141,777, Patented August12,1873.

g I gf/gamgmfm UNITED STATES PATENT OFF CE.

THOMAS A. EDISON, OF NEWARK, NEW J ERSEY, ASSIGNOR TO HIMSELF AND GEORGEHARRINGTON, OF WASHINGTON, DISTRICT OF COLUMBIA.

l-MPROVEMENT lN Specification forming part of Letters Patent No.141L777, dated August 12, 1870; application filed March 13, 1873.

To all whom it may concern Be it known that I, THOMAS A. EDISON, of

Newark, in the county of Essex and State of v burning of thecontact-p0ints by the spark are sources of constant annoyance.

My present invention is made for'preventing" the points burningonh-andfor avoiding adjustment of the retractile armature-springs.

I make use of metallic contact-points within a liquid, such as glycerineor water,so that the motion of one contact-point nearer to or fartherfrom the other raises and lowers the electric tension in thetelegraph'line, and operates a distant magnet without forming a spark orbreaking the circuit.

In the drawing, Figure 1 is a side view of the relay-magnet with thecircuit-cup in section, and Fig. 2 is a side view of the distant magnet.

The finger-key a is in a circuit from the battery I); so also are thecoils of the relay-magnet c. The armature d andits lever f are moved bythe spring e in one direction, and by the magneto in the other. Thecircuit-cup gis made to contain water, glycerine, or other suitableliquid. In the bottom is the screw or point i, connected with thecircuit-wire 7a, and the movable point or screw l passing through thelever f is connected with the other circuitwire m, extending to thedistant magnet 11. The battery 9 isin the circuit .to the magnet a; andit will now be understood that by adjusting the point Z nearer to orfarther from i the proportion of current passing to the mag net a can beadjusted so that, when the point Z is moved by the magnet c nearest toi, the current from 1 will be su'fliciently powerful to energize themagnet in and draw down its armature u,- but when the circuit-to themagnet 0 is broken at the key a, or otherwise, the

movement of the point Z away from i will lessen the tension in thecircuit k m by the resistance of the intervening liquid, and weaken thepower of the electro magnet a, so

that its spring or weight t will draw away itsarmature.

The movement of the armature u may be made operative in effecting anydesired telegraphic operation to which it is adapted. I, however, employthe same especially as a sounder, and in that case the battery 1' andcircuit k m are local.

I am aware that contact-points within a liq uid, such as oil orglycerine, have been em ployed in the circuit-breaker of an electricengine; In my improvement the circuit is not broken, but therelay-magnet or sounder is operated by rise and fall of tension, and thecontact-points are adjustable instead of varying the armature-spring ofthe magnet.

I claim as my invention The adjustable contact-points acting within aliquid, in combination with thehelix, armature, and spring of a sounderor relay, as set forth.

Signed by me this 7th day of March, A. .1). 1873.

THOMAS A. EDISON.

Witnesses:

Gno. T. PINCKNEY, Gems. H. SMITH.

